Design of the dual-band common-aperture optical imaging system

In this paper, a visible/near-infrared (NIR) co-aperture optical system based on an internal reflecting lens is proposed, where the light propagates by reflecting inside the lens, simplifying the co-aperture structure, reducing the number of lenses while enlarging the field of view, and using dichroic mirrors to complete the spectral separation to realize the simultaneous imaging of visible and near-infrared light. The optical system is simulated and optimized by optical design software, and tolerance analysis and scattered light analysis are performed. For blurred images caused by sensitive tolerances, image restoration of the blurred images is performed using SRN-Deblurnet. The system extends the total field of view to 30°and provides high-quality images in both bands simultaneously. Monte Carlo tolerance analysis confirms the manufacturability of the system. The internal reflector lens structure helps to correct the external aberration of the axis, reducing the number of mirrors and the difficulty of adjustment, while the SRN-Deblurnet reduces the impact of sensitive tolerances. • The use of internal reflection lenses instead of the traditional reflection structure, expanding the field of view and optimizing the system structure. • The off-axis lens and the machining of the rear surface of the dichroic mirror are achieved using a single plastic aspheric lens, resulting in good imaging quality. • The use of SRN-Deblurnet reduces the impact of sensitive tolerances on imaging.